The present invention relates to a numerical control information generating apparatus which generates numerical control information for controlling a numerical control lathe with two headstocks.
Recently, a numerical control lathe with a first headstock and a second headstock has been contrived, along with a numerical control information generating apparatus which generates numerical control information to machine a work using the numerical control lathe.
FIG. 1 is a block diagram showing an example of the prior art numerical control information generating apparatus. The input data SA which are input to a data input section 2 via a keyboard 1 by an operator are divided into three different types of data, that is, a blank shape SB, a machining shape SC and a first machining/second machining divisional position SD and are respectively stored in the blank shape storage section 3 and the machining shape storage section 4 and the first machining/second machining divisional position storage section 5. Both the blank shape SB stored in the blank shape storage section 3 and the machining shape SC stored in the machining shape storage section 4 are read into a machining portion extraction section 6 which extracts a maching portion SE and transmits the machining portion SE to a first machining/second machining portion dividing section 7.
By the first machining/second machining divisional position SD which is read into the first machining/second machining portion dividing section 7 from the first machining/second machining divisional position storage section 5, the machining portion SE read into the first machining/second machining portion dividing section 7 from the machining portion extraction section 6 is divided into both the first machining portion which the first headstock machines and the second machining portion which the second headstock machines and is consequently transmitted to a machining process determining section 8 as a divided machining portion SF. The divided machining portion SF which is read into the machining process determining section 8 from the first machining/second machining portion dividing section 7 is analyzed and a machining process which the first headstock provides to the first machining portion and also another machining process which the second headstock provides to the second machining portion are determined and then transmitted to a numerical control information generating section 9 as a machining process SG. The machining process SG transmitted from the machining process determining section 8 is read in the numerical control information generating section 9 and converted into numerical control information SH to be output in a mode such as a magnetic disk 10.
FIGS. 2A and 2B are drawings for explaining an example of dividing the machining portions in the above-mentioned prior art numerical control information generating apparatus. First, an operator stores the three different types of data, that is, the blank shape SB, the machining shape SC and the first machining/second machining divisional position SD respectively in the blank storage section 3, the machining shape storage section 4 and the first machining/second machining divisional position storage section 5 through the keyboard 1 and the data input section 2. Then, the machining portion extraction section 6 extracts a portion to be machined from the blank shape SB stored at the blank shape storage section 3 and the machining shape SC stored at the machining shape storage section 4 and transmits the extracted portion to the first machining/second machining portion dividing section 7 as the machining portion SE. Then, the first machining/second machining portion dividing section 7, wherein the machining portion SE is read, divides the machining portion SE into the first machining portion and the second machining portion according to the first machining/second machining divisional position SD which is stored at the first machining/second machining divisional position storage section 5. The first machining portion and the second machining portion, as divided and shown in FIG. 3A, are respectively provided with the first machining by the first headstock and the second machining by the second headstock as shown in FIG. 3B.
In the case of the above described prior art numerical control information generating apparatus, the operator in advance determines a divisional position for dividing a single machining portion into the first machining portion and the second machining portion. However, in the case of the numerical control lathe where an output of the spindle motor of the first headstock differs from that of the second headstock, there is admittedly a problem in that the operator is not able to allocate a divisional position for dividing a single machining portion into a portion to be machined by the first machining and another portion to be machined by the second machining at a suitable position unless he/she is the skilled in machining, since it must divide a single machining portion into the first machining portion and the second machining portion in order to equalize the machining time of a headstock with that of another headstock.